It is well known that chronic kidney disease is a risk factor for atherosclerosis. The present study was conducted to identify any relation between the estimated glomerular filtration rate (eGFR) and coronary plaque characteristics using integrated backscatter intravascular ultrasound (IB–IVUS), which can detect coronary plaque composition. We performed IB–IVUS for 201 consecutive patients undergoing percutaneous coronary intervention, and they were divided into 3 groups according to the eGFR values (group 1 [n = 20], ≥90 ml/min/1.73 m²; group 2 [n = 123], 60 to 90 ml/min/1.73 m²; and group 3 [n = 58], <60 ml/min/1.73 m²). Coronary plaques in nonculprit lesions on 3-dimensional analysis were evaluated using IB–IVUS. The baseline characteristics were similar, except for older age and a greater prevalence of men in group 3. IB–IVUS showed a percentage of lipid volume of 44.7 ± 5.0% in group 1, 53.6 ± 6.2% in group 2, and 63.5 ± 6.2% in group 3 (p <0.01), with a corresponding percentage of fibrous volume of 53.9 ± 4.9%, 45.1 ± 6.0%, and 35.3 ± 6.1%, respectively (p <0.01). The eGFR correlated significantly with both parameters (r = −0.68, p <0.001 and r = 0.68, p <0.001, respectively). In conclusion, lower eGFR levels were associated with greater lipid and lower fibrous contents, contributing to coronary plaque vulnerability.